Thread insert



l Nov. 28, 1944.` H. J. FINDLEY THREAD INSERT Filed Nov. 12, 194s Illl.

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FIG-4- INVENTOR. HOI/#R0 J.' F//VLE Y Patented Nov. 28, 1944 THREAD INSERT Howard J. Findley, Shaker Heights, Ohio,` lassignor to Eaton Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Application November 12, 1943, Serial No. 509,995

4 Claims. (Cl. 8546) This invention relates to thread inserts or bushings of the kind made from helically wound wire and aims to provide a novel insert of this character in which onev portion is f a` different size or shape than other portions so as to grip one of the threaded members with which the insert is used.

Another object of my invention is to provide a thread insert of the kind mentioned having one or more convolutions in an intermediate portion thereof wound to a smaller size or diameter than its end portions, so as to grip a threaded member when the latter is screwed into the insert.

A further object of my invention is to provide a novel thread insert of the character referred to having a relatively reduced or tapered end portion which facilitates the application of the insert to the threaded opening andgrips an externally threaded member when the latter is screwed into the insert.

-Other objects and advantages of the invention will be apparent from the following description whenA taken in conjunction with the accompanying sheet of drawings in which Fig. 1 is a longitudinal sectional view taken through one form of my thread insert and showing the same in an internally threaded opening but without any threaded male member screwed into the insert.

Fig. 2 vis a view similar to Fig. 1 but showing a threaded male member screwed into the insert.

Fig. 3 is a longitudinal sectional View taken through another form of my thread insert and showing the same in an internally threaded or female member and without any threaded male member therein.

Fig. 4 is a longitudinal sectional viewV similar to Figs. 1 and 3 but illustrating stilll another form of my thread insert; and

Figs. 5 and 6 are end views thereof.

More detailed reference will now be made-to Figs. 1 and 2 in which I show one form of my thread insert III being used in an internally threaded opening I I of a female member or body I2 for forming a threaded connection between such member and an externally threaded `male member or body I3. The internal thread I 4 of the member I2 may be a helical thread of a.

l relatively soft material such as aluminum, wood,

plastic or the iike and in which 'it is desirame to use. the insert I3 as a bushing orV adapter and for the purpose of Vobtaining al stronger connection for the externally threaded member I3. In this instance the externally threaded member I3 is a screw having a head I5 and a stem carrying a helical thread I3 of a standard or conventional form and which is of the same pitch as the thread I4 of the member I2. The screw I3 is here shown as being used to clampingly connect a plate I'I or the like with the member I2. 'A washer I8 may be used under the head of the `screw I3.

The insert I0 is formed by helically winding a strand of wire so as to form a bushing or sleeve in which the convolutions have substantially the same pitch as the threads Il and I6. The wire used in forming the insert I0 is of a doubleedged cross-sectional shape such that when wound into an insert or bushing portions of the wire will form a continuous internal thread Illa and oppositely extending portions will form a continuous external thread IIJb. In this instance the wire strand is of substantially diamondshaped cross-section and the internal and external threads IIIa and Ib formed thereby on the insert are of a standard or conventional form corresponding respectively with the thread I6 of the screw I3 and the thread I4 of the member A distinguishing feature of my insert I0 is that a portion thereof is of a differentsize or shape than Vits other portions so as to -produce a gripping or holding action on one or the other of the threaded members with which the insert is used. 4

smaller size or diameter than the end portionsV of the insert. l

In Fig. 1 I show the insert I3 as having been screwed into the internally threaded opening II of the member I2 and in readiness to4 receive the screw I3 or other externally threadedmember to be used therewith. In Fig. 2 I show the screw I3 with the stem thereof screwed into the insert I0 and with the head in clamping engagement with the plate I1 and Vwasher I3. When the screw I3 `is advanced into the insert I0, the threaded stem of the screw moves through and expands the convolutions forming the relatively reduced sec-- tion I9 and these convolutions.thereafterexert a gripping and holding eiect on the screw which effectively prevents the screw from working loose. The locking or holding effect thus provided between the insert and screw effectively retains the latter against accidentally loosening but will not prevent the screw from being unscrewed if it should be desirable to do so.

The gripping or holding elTect just described above for the insert lll can be obtained in various other ways; for example, in Fig. 3, I show an insert 2| which is similar to the insert l0 but which has an end section 22, differing in lsize or shape from the remaining portions .of the insert. The insert 2l is-also formed of helically wound wire and the relatively reduced end section 22 thereof may be formed by winding the wire for this portion to a relatively smaller diameter than for the other portions of the insert. When a screw or other externally threaded member is screwed into the insert 2|, the relatively' reduced section 22 is expanded by the externally threaded member and, acts on the latter to grip or hold the same against accidental loosening. vThe relatively reduced end section 22 also facilitates the operation of screwing the insert into' the internally threaded opening 23 of the body 24 with which`the insert is to be used.

In Figs. 4, 5 and 6 I show still another thread insert 25 which embodies the holding or locking feature described above.v The insert 25 also `has a relatively reduced end section 26 which will exert a holding or locking action on an externally threaded member when the latter is screwed into the insert. The relatively reduced section 26 .is of a tapering form and also varies from a circular or cylindrical shape to an oval shape at the extreme end of the insert as shown in Fig. 6. The taper on the relatively reduced section 26 and the change from round to oval cross-sectional shape enables this portion of the insert to exert a strong gripping action on an externally threaded member when screwed into the insert.v The relatively reduced size of the end section 26 of this insert facilitates the operation. of screwing the insert into the internally threaded opening 21 of the body 28 in which the insert is to be used.

Although I have not shown 'threaded members actually screwed into the inserts 2| and 25 of Figs. 3 and 4; these inserts would resemble the insert I0 as shown in Fig. 2 afte'r such externallythreaded members have been v-screwed thereinto. In other words, the relatively reduced 4sections 22 and 2B of the inserts 2l and. 25 will be expanded to substantially cylindrical shape by the externally threaded members which are screwed into these inserts.

From the foregoing description and the accompanying drawing it will now be readily understood that I have provided a novel form of thread insert, 'of the type formed from helically wound wire, and in which a portion of the insert is formed to a different size or shape than its other portions and exerts a holding or gripping effect on one of the threaded members with which the insert is used.

While I have illustrated and described my novel thread insert in more or less detail it will be understood, of course, that I do not wish to be correspondingly limited but regard my invention as including all changes and modifications coming within the spirit of the invention and the scope of the appended claims.

Having thus described my invention, I claim: 1. A thread insert of the character described for use with male and female members having preformed threads thereon comprising, a bushing formed of helically wound wire of a double-edged cross-sectional shape to provide internal and external helical threads on the bushing for cooperation with the preformed threads of said male and female members, the intermediate portion of said bushing being of a different size than its end portions so as to produce a gripping action between the bushing and one of said members.

2. A thread insert of the character described for use with male and female members having preformed threads thereon comprising, a bushing .of helically coiled wire of a double-edged cross-sectional shape to provide internal and external helical threads on the bushing 'for cooperation with the preformed threads of said male and female member, said bushing having one or more convolutions in an intermediate porber therein, the intermediate portion of said bushing being of relatively reduced diameter so as to grip said threaded male member.

4. An insert for use in an internally threaded opening and adapted to receive a threaded member therein comprising, a bushing formed of helically wound' wire of a double-edged cross-sectional shape so as to provide the bushing with an external helical thread enabling it to be screwed into said'openng and an internal helical thread enabling it to receive said threaded member therein, said bushing having one or more convolutions in an intermediate portion thereof Wound to a relatively smaller-diameter than its end portions so as to grip said threaded member.

HOWARD J. FINDLEY. 

